ext4: update comments regarding ext4_delete_inode()

ext4_delete_inode() has been renamed for a long time, update
comments for this.

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index a432634..3cb267a 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -592,7 +592,7 @@
 
 	/*
 	 * set the  i_blocks count to zero
-	 * so that the ext4_delete_inode does the
+	 * so that the ext4_evict_inode() does the
 	 * right job
 	 *
 	 * We don't need to take the i_lock because